Augmentor fob jet propulsion hav



Aprfl 25, 1950 BQPMANN 2,505,660

AUGIIENTOR FOR JET PRO LsIoN HAVING BORE Rows 0F TURBINE DRIVING BLADINGTHA DRIVEN AIR BLADING Filed Jan. 13, 1944 .B ShoetQ-Shoet 1 lndu czed nr y I 2 From Turbine 5- H l3 p- 1 55;

aw /I/If/l Mme WMMV April 25, 1950 AUGNENTOR FOR JET PR Filed Jan. is,1944 BAUMANN OPULSION HAVING IORE ROWS O TURBINE DRIVING BLADING DRIVENAIR BLADING 8 Sheets-Sheet 2 lNwrlvrog K. BAUMANN Aprfl 25, 1950AUGHENTOR FOR JET PROPULSION HAVING MORE ROWS OF TURBINE DRIVING BLADINGTHAN DRIVEN AIR BLADING Filed Jan. 13, 1944 8 Sheets-Sheet 3 I H 3 IIWH/M Apnl 25, 1950 K. BAUMANN 2,505,660

aucmam'oa FOR JET PROPULSION HAVING KORE ROWS 0F TURBINE muvme 3mm: mmDRIVEN AIR BLADING Filed Jan. 13, 1944 a Sheetsn-Shoet 4 RNtY Aprifi 5,150 K BAUMANN 2,505,660

AUGMENTOR FOR JET PROPULSION HAVING MORE ROWS 0F TURBINE DRIVING BLADINGTHAN DRIVEN AIR BLADING 8 Sheets-Sheet 5 Filed Jan. 13, 1944 nvvs/vr /vf i M My /9 om/vs Y Mp 1950 K. BAUMANN 3,505,550

AUGMENTOR FOR JET PROPULSION HAVING MORE ROWS 0F TURBINE DRIVING BLADINGTHAN DRIVEN AIR BLADING Filed Jan. 13, 1944 8 Sheets-Sheet 6 m MM, WMMUAPHHMZS 1950 K. BAUMANN 2,505,660

AUGMENTOR FOR JET PROPULSION wwmc MORE Rows 0F TURBINE DRIVING summc muDRIVEN AIR smnmc Filed Jan. 13, 1944 8 Sheets-Sheet 7 II ""0110 k IN VEN TOR. Err! fiaumazm mum ATTORNEYS v w fwd pmfi 11w 19m BAUMANN 2AUGMENTOR FOR JET PROPULSION HAVING MORE ROWS 0F TURBINE DRIVING BLADINGTHAN DRIVEN AIR BLADING Filed Jan. 13, 19M 8 Sheets-Sheet 8 E u v 1 N UIN V EN TOR. IEzrZ Ba zmzamz ATTORNEYS Patented Apr. 25, 1950 TATESPATENT 1*! FFICE Karl Baumann, Knutsforcl, England, assignor toMetropolitan-Viol tors Electrical lCompany Limited, London, England, acompany of Great Britain application January 13, 1944, Serial No.518,165 In Great Britain ilctober It, 1941 Section ll, Public Law 690,August 8, 1946 Patent expires lllctober 14, 196i 6 Claims.

This invention relates to internal combustion power plant for propulsionin air of the kind wherein the energy in the rearwardly exhaustingproducts of combustion is utilised at least to assist in the propulsionby so-called jet action, such plant being notably but not exclusivelyemployed for the propulsion of aircraft.

The invention furthermore specifically concerns an internal combustionpower turbine component operated by the exhausting products ofcombustion and arranged to drive or work upon air additional to thatused for the internal combustion, whereby essentially to increase thepropulsion effect in at least one way.

The present invention provides a thrust augmentor comprising incombination at least two coaxial contrarotationally bladed turbinerotors all adapted to be driven by a flow of high velocity combustedgas, and each driving air screw or ducted fan blading which is at agreater mean diameter than that of the turbine blading, whilst at leastone of said rotors has more turbine blading stages than air screw or fanblading stages.

The contra-rotational augmentor arrangement just above set forthaccording to the invention enables the weight of this part of the plantto be reduced because of the essentially relatively smaller number ofair augmenting stages, there being more than two turbine stages, wherebyto use efficiently at relatively low peripheral speeds the heat dropavailable in these turbine stages. This is an important aspect, sincethe peripheral speed of the air screws or fan stages is limited byreason of compressibility effect, which causes a serious loss ofefficiency when the relative veelccity of the air past the bladesapproaches the velocity of sound.

It will be appreciated furthermore, that by reason of the contrarotation of the stages the gyrostatic effect thereof is minimised, thisbeing important when aircraft is required to change direction quickly.The fact will be appreciated that were the number of air screws or fanstages made equal to the number of stages of turbine driving them, theheat drop available per/ stage in the gas entering the contra-rotationalturbine would be many times the heat rise per stage of the air screws orof the fan, while on the other hand the peripheral speed of thecontra-rotational inner turbine stages is essentially lower than that ofthe air screws or fan blades. Whilst normally two rows of air screws orfan stages are sufficient for the acceleration or the compression(respectively) of the air required, more than two rows of turbine stagesare essentially required to utilise eihciently the available energy inthe gases such as the gases leaving the compressor turbine beforefurther expansion in the jet nozzle.

While convenient arrangements of parts of the plant lead naturally tothe adoption of a direction of flow of the products of combustionthrough the compressor turbine first and the power turbine subsequently,this order is in no way essential, and arrangements in which the flow isthrough the power turbine first and the compressor turbine subsequently,which latter then exhausts to the propelling nozzle, are within thescope of the invention, although not illustrated.

Several preferred embodiments of the invention will now be respectivelydescribed by way of example with reference to the accompanying drawings,which are purely diagrammatic views in conventional form illustratingdifferent forms of augmentor. For the sake of simplicity, suchconstructional details as glands, bearing seals, joints or flangesrequired for assembly, and so on, are omitted.

Fig. l is a radial section of the thrust auge mentor and adjacentcooperative elements of an internal combustion turbine power plantaccording to one embodiment of the present invention, in which a row offixed blading is interposed between the compressor and the powerturbines.

Fig. 2 is a view similar to Fig. 1, but showing the last stage of thecompressor turbine immediately adjacent to the intake of the powerturbine, and illustrating modified means for supporting the bearings forthe power turbine rotors.

Fig. 2a is a detail section on the line 211-20: in Fig. 2.

Fig. 3 is a view similar to Figs. 1 and. 2, but showing means carried bythe last stage of the compressor for supporting the bearings for therotors of the power turbine.

Fig. 4 is a radial section of the augmentor, showing another means forsupporting the rotors of the power turbine.

Fig. 5 is a radial section of an augmentor which embodies the turbinestage arrangement of Fig. 2

combined with that shown in Fig. 4 to provide a four stage arrangement.

Fig. 6 is a radial section of another form of four stage arrangement forthe power turbine.

Fig. 7 is'a view similar to Fig. 6, but showing a modified arrangementof the fan blading relatively to the rotors of the power turbine.

Fig. 8 is a radial section of a six stage power turbine blading.

Fig. 9 is a view of a four stage arrangement similar to that shown inFig. 4. but showing modified means for supporting the bearings for thesecond and third stages.

Fig. 10 is a radial section of a modified arrangement of a four stagepower turbine rotors employing stationary guide blading.

Fig. 11 is a view similar to Fig. 10, but employing five stages and amodified arrangement of the stationary guide blading.

Fig. 12 is a view similar to Figs. 10 and 11, but showing a six stagepower turbine.

Fig. 13 'is a radial section of a portion of a multiple tier blading forthe turbine of the augmentor. and showing a cross-over air duct leadingto the combustion air compressor.

Fig. 14 is a view 01' a multiple tier blading similar to that shown inFig. 13, but showing modifled duct. arrangement for gases exhausted fromthe power turbine.

Fig. 15 is a radial section of an augmentor similar to that shown inFig. 3, but showing unshrouded air screws, and in which the nozzle wallsare rotatable with a stage of the power turbine.

Fig. 16 is a radial section of another form of augmentor, in which oneof the nozzle walls is rotatable with a stage of the power turbine, andshowing a modified mounting of the air screws on the rotors of the powerturbine.

Fig. 17 is a radial section of a form of augmentor similar to that shownin Fig, 9, but showing a modified arrangement of the rotors of the powerturbine for driving air screws, and employing additional turbineblading.

Fig. 18 is a diagrammatic longitudinal section of an internal combustionpower turbine plant for jet propulsion, embodying the thrust augmentorof Fig. 1.

Fig. 19 is an enlarged detail view of a portion of the fan blading ofthe augmentor shown in Figs. 1 and 18.

Fig. 20 is an enlarged section of a portion of the turbine blading,taken on the line 2!i-29 in Fig. 18.

Fig. 21 is a longitudinal section of an internal combustion turbineplant embodying the structure shown in Fig. 13.

Similar parts are designated by the same reference characters in thedifferent figures.

Referring to Figs. 1, .18, 19 and 20 of the drawings, at la and lb areshown annular walls which constitute the entry to the final expansionjet for propulsion by the exhaust gases from the internal combustionturbine T for driving the compressor C, the compressor turbine beinglocated immediately to the right in Fig. 1 (and all the other figures)so that the exhaust from the compressor turbine is connected with theright-hand end of the annular wall members la and lb although as shownin Figure 1, there may be interposed between the compressor turbine andthe power turbine of the present invention a row 2 of fixed bladingwhich can be carried by a diaphragm 3 having integal with it or fixed toit a non-rotating stub axle 4. The compressor turbine T is arranged toreceive combusted gases from the combustion chamber CC through anannular row of fixed blading c in the discharge duct oi the combustionchamber.

The augmentor shown in Figs. 1, 18, 19 and 20 has threecontra-rotational stages of power turbine blading (in this case lowpressure) and two stages of fan blading, the latter being located in theannular duct between the annular wall member Ia and an outermost wall 5into the righthand end of which duct the air to be power driven mayenter as shown by the upper 01 the two arrows in Fig. 1. As hereinbeforementioned, when the stages indicated at Ia and 11a are air screws theoutermost wall 5 will be omitted. The air screws may assume variousshapes as desired: they may be in the form of propellers.

In Figures 1 to 12, and 15 to 20, the stages 01' the augmentor of bothpower turbine and fan or air screw are counted from right to left namelyin the direction of air or gas flow, and are all indicated by Romannumerals.

In Figures 1, 18, 19 and 20 the first and last augmentor turbine stagesI and III are carried by discs 6 and 1 respectively, rigid with a sleeveshaft 8 having ball bearings 9 and III the inner races of which arecarried by the stub axle '4. The middle row of turbine blading II iscarried by a disc ll having a ball bearing I2, the inner member of whichis carried on the outer periphery of the sleeve shaft 8.

The contra-rotational ducted fan stages (or it may be alternatively airscrews) are shown at Ia and IIa, these constituting with the stages IIand III of turbine blading "double tier stages.

In the arrangement illustrated by Figure 1, and in Figures 18, 19 and 20it will be seen that according to one aspect of the invention the secondstage 11a of fan blading is rotated by the two stages I and III ofturbine blading, whilst the first stage Ia of the fan blading is rotatedby the middle stage II of the power turbine.

The arrangement shown in Figure 2 differs from that shown in Figure l inthat there is no fixed guide blading 2; at 2a is indicated the lastrotating stage of the compressor turbine, whilst the axle 4 instead ofextending from the fixed diaphragm 3 is carried through radial webs,which are preferably streamlined with respect to the gas and air flow,by the wall members lb, la and 5, one of these webs being indicated atl3 and streamlined as shown in Fig. 2a. These or equivalent webs may beassumed to be used in all of the illustrated arrangements, as and wherenecessary.

By reason, as preferred, of the immediate juxtaposition of the finalblading row 2a of the compressor turbine and the first row I of thepower turbine rotating in the opposite direction, it becomes convenientto utilise a greater heat drop in the blades 2a and to discharge the gasfrom those blades with a velocity relatively to the nonrotatingstructure which has a tangential component in the direction of movementof the adjacent power turbine blading I while arranging the crosssectional contours and speeds of this and the succeeding blade rows IIand III in such manner that the gas shall leave the blades III insubstantially an axial direction. Associated with this acceptance by thepower turbine of swirl in the incoming gas, corresponding provision canbe made in the ducted fan for a change of tangential component of airvelocity during passage through the two fan stages, for instance by theintroduction of guide blades Hill at the inlet, or by constituting thewebs II in the form of guide blades,

or by both means. It will be appreciated that the relative tangentialcomponent of air velocity involved will be much less than that of thegas made use oi in the power turbine on account of the greater rate offiow by weight of air than of gas.

The arrangement shown in Figure 3 only differs from the arrangementsshown in Figures 1 and 2 in that the ball bearings 9 and ill for thepower turbine stages HI and I have their inner races associated with ashaft extension to carried by or integral with the disc 21: carrying theblading to, being the last stage of the compressor turbine.

It will be appreciated that in the arrangements shown in Figures 2 and 3the power turbine stages I and III rotate in the opposite direction tothat of rotation of the final stage 2a of the compressor turbine. Itwill also be noticed that the fan blading stages Ho and Ia areassociated with the lowest pressure power turbine stages II and III:whilst this is preferred it is not essential as will hereinafter appear.

Referring to Figure 4, it will be seen that the second stage Ila of thefan blading is driven by the fourth stage IV of the power turbineblading carried by a double tiered disc (or equivalent) it fixed on acentral shaft db which is carried at each end from the fixed wall memberlb and the housing of a row of stationary guide blading 2 by radialmembers or discs i311, l3?) through ball bearings it, it respectively.The blading of the second turbine stage II is carried on a disc orequivalent to also secured to the shaft ib. The first stage I of turbineblading is carried by a disc ill integral with or connected to a sleeveshaft it which is carried through ball bearings it] and m by the shaftib.

The first fan blading stage Ia and the third power turbine blading stage111 are both carried at one end of a sleeve M the other end of which iscarried by the outer periphery of the power turbine blading stage I. Theinner periphery of the turbine blading stage III is secured to orintegral with a diaphragm 22 or an inner foundation ring. The row ofstationary guide blading 2 shown is similar to the guide blading shownin Fig. 1.

Figure 5 shows a four turbine stage augmentorcombining features of thethree turbine stage arrangement of Figure 2 and the four turbine stagearrangement of Figure 4, as will be readily apparent from an inspectionof Figure 5, a speciidc description of which is therefore consideredunnecessary.

The arrangement of Figure 6 shows another four stage power turbineembodying features of earlier figures, as will be readily apparent froman inspection of Figure 6 so that again a specific description thereofis considered unnecessary.

Figure 7 shows an arrangement which dififers from the arrangement shownin Figure 6 in the feature that the fan blading stages Ia and Ho. are,

so to speak, shifted to be in the centre of the length of the axialturbine stages, namely by carrying the 'blading stage 11s at the right-.hand and of a foundation ring or cylinder 23, the left-hand end ofwhich is riveted or otherwise fixed to the outer ring it of the turbineblading stage IV. The fan blading of stage I0. is similarly fixed to theleft-hand it which at its right-hand end is fixed to the sleeve it (seeFigures 5 and 6). The fan blades need not however be located as shown;they may for instance both be located upstream or downstream relativelyto the power turbine stages,

end of a ring 6 and in the latter case the blade root diameter may besmaller than the tip diameter of the turbine blades.

The arrangement shown in Fig. 8 differs from earlier arrangements in themain in that there are six stages of power turbine blading, alternatestages being carried by inner and outer rotor cylinder members 26 and 21respectively. The rotor cylinder 26 is shown as being carried centrallyalong its length by a disc 28 fixed to a sleeve shaft 29. The rotorcylinder 21 is shown as carried from its end through the blading stage I'by a disc 30 fixed to a sleeve shaft 31 coaxially surrounding thesleeve shaft 29, the two rotors having bearings as shown.

It will be understood that the disc members 28 and 30, in fact any ofthe disc members shown in any of the figures, may if desired be replacedby annularly dished discs giving in relation to their weight,considerable stiffness in the axial direction but permitting someflexibility in the radial direction relatively to the non-rotatingstructure.

Figure 9 shows an arrangement havin four stages of turbine blading, thefirst and fourth of which are carried, (generally after the manner shownin Figure 4) from a central shaft lb. The second and third turbinestages are shown as carried by discs 32 and 33 which at their innerperipheries are connected to a sleeve shaft 34. This shaft is carried inbearings 35 the outer races of which are carried by a sleeve 36, in turncarried by a disc or the equivalent 3'! the outer periphery of which iscarried by a sleeve or foundation ring 38 for a row of fixed guideb1ading 39. The outer periphery of this guide blading 39 is carried bythe annular duct wall la and preferably connected by webs I00 with theouter wall 5.

iii

Figures 10, 11 and 12 show further arrangements the features of whichwill be readily apparent upon inspection, after perusal of the maiorityof the description of the arrangements of the earlier figures; thereforeno specific description is considered necessary of Figures 10. 11 and12.

Referring to Figures 13 and 14, these show augmentor" arrangementsembodying inter alia multiple tier turbine blading involving, as will bereadily apparent from inspection of these figures, the reversal of fiowof the gases from the compressor turbine T, the final stage of which isindicated at 2a, the reversal of flow taking pace in annular duct 40 inFig. 13 and in ducts all and ll in Fig. 14. At M in Figs. 13 and 21there is indicated a curved, cross-over air duct leading to thecombustion air compressor C which duct may tap off air in the annularduct in 5 and augmented by the contra-rotational fan blading stages Iaand 11a. The compressor C delivers compressed air to a combustion cham-I ber CC which discharges products of combustion therefrom to thecompressor turbine T, the latter discharging the products of combustionto the stages I and II and then through the duct 7 and 11a, the outernozzle member being omitted: also, as an example, the nozzle wall ia (ofFigures 1 to 12) is shown as rigidly attached to the outer shrouding ofthe power turbine stage III as by welding, as shown so as to rotatesolidly with the-latter.

In the arrangement illustrated by Figure 16, the unducted but notnecessarily individually unshrouded air screws Ia and Ila are driven bythe arrangement substantially as illustrated by Figure 7 but, apartpossibly from the omission of the outer nozzle wall 8, and outer part orparts of the radial webs iii the ring or cylinder 23 (of Figure '7) ismodified to extend left-wardly as at 23a, whilst the ring 25 of Figure 7is made longer as shown at 25a in Figure 16, to bring the air screwstage Ia close to the stage Ila: furthermore the nozzle wall la may besolidly connected at its right-hand end to the shrouding 24 as byriveting it thereto as shown.

Referring lastly to Figure 17, it will be seen that the arrangement hereillustrated is in principle the same as certain of the arrangementspreviously herein illustrated, and the augmenting air blading is inthe'form of propellers Ia and Ila, these latter being associated withthe power turbine stage 111a: and N as double tier members, the turbinestages 111a: and IVy receiving the gases from the stages I and I1through fixed guide blading 39. It may be that in practice the bladingstages mm and 1V3 might pass the gases without much work being done onthis blading, or IIIa: and Ivy may represent simple orifices: in eithercase it will of course be necessary to provide additional turbineblading stages which are indicated at 12 and H2 mounted as shown.

In Figures 15 and 16 the walls to and lb of the nozzle are shown asfixed to the final rotor stage so as to rotate therewith, and in Fig.1.5 the wall as is shown as fixed to the sleeve 9 of the final rotor bythe web 33, and it will be ap preciated that if found convenient theinner most wall member lb inFi g. 16 may also be rigidly fixed to afinal rotor, as by the web (19 as shown in Fig. 15, or fixed similarlyto any rotor having a sleeve which extends beyond the final rotor stage.

1 claim:

1. A propulsion system for aircraft comprising an air compressor, acombustion chamber connected to said chamber to receive air therefrom, afirst turbine arranged to receive cornbusted gases from said chamber andconnected to said compressor for driving the latter, a reaction jetthrust nozzle, an inner annular duct for conducting combusted gasesexhausted from said turbine to said nozzle, an outer annular ductleading to said nozzle, and a second turbine disposed between said firstturbine and said nozzle for augmenting the thrust due to the flow ofcombusted gases through said nozzle and for reducing the velocity ofsuch flow, said second turbine comprising two nontrarotational rotorscarrying an inner tier of driving blading rows arranged in said innerannular duct to be operated on by said combusted gases and an outer tieroi driven blading rows arranged in said outer annular duct. at least oneof said rotors having a plurality of driving blading rows driving asmaller number of driven blading rows.

2. A propulsion system as defined in claim 1, wherein said aircompressor, combustion chamber and first and second turbines are alignedaxially with said jet nozzle, and including ducts for straight throughflow of air from the compressor to the combustion chamber and ofcombusted gas from the combustion chamber to the jet nozzle.

3. A propulsion system as defined in claim 1, wherein the drivingblading rows on the respective rotors of said second turbine are spacedaxially and the rows of driving blading rows of said rotors are inadjacent relation, and including a row of relatively fixed guide bladingmounted between the axially spaced rows oi driving blading rows on saidrotors.

4. A propulsion system as defined in claim 1, wherein the drivingblading rows of said second turbine are arranged in successive tiers,and including means for reversing the direction of flow of gas throughsuccessive tiers.

5. A propulsion system as defined in claim 1, wherein the drivingblading rows of said second turbine are arranged in successive tiers,and including means for reversing the direction of fiow of gas throughsuccessive tiers, and ducts leading from said outer annular duct to saidcompressor for supplying air to the latter.

6. A propulsion system as defined in claim 1, wherein the drivingblading rows of said second turbine are spaced axially from the bladingof said first turbine, and including a fixed row of guide bladingmounted in the space thus provided.

KARL BAUMANN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 790,406 Stumpf May 23, 19051,929,773 Goddard Oct. 10, 1933 2,026,885 Goddard Jan. 7, 1936 2,396,911Anxionnaz et al. Mar. 19, 1946 2,405,919 Whittle Aug. 13, 1946 FOREIGNPATENTS Number Country Date 401,863 France Aug. 12, 1909 411,473 FranceApr. 12, 1910 OTHER REFERENCES Serial No. 367,666, Anxionnaz et al. (A.P. C.)

pub. May 25, 1943.

